Assawawiroonhakarn S, Apiwattanakul N, Pakakasama S, Hongeng S, Anurathapan U, Yoksan S, Klinmalai C, Sae-Chew P, Techasaensiri C. Immunogenicity of Vero Cell Culture-derived Japanese Encephalitis Vaccine in Pediatric and Young Hematopoietic Stem Cell Transplantation Recipients.
Pediatr Infect Dis J 2021;
40:264-268. [PMID:
33427799 DOI:
10.1097/inf.0000000000003007]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND
Children and young adults undergoing hematopoietic stem cell transplantation (HSCT) typically lose their immunity to vaccine-preventable diseases, including Japanese encephalitis (JE). Revaccination against JE in this population has not been well characterized.
METHODS
This prospective study evaluated the immunogenicity of inactivated Vero cell culture-derived JE vaccine in children and young adults (<25 years of age) who had completed HSCT >1 year prior. Each patient received inactivated Vero cell culture-derived JE vaccine at enrollment and 1 month after enrollment, as well as a booster dose 13 months after enrollment. Serum JE plaque reduction neutralization test and JE-specific T lymphocyte count assay were performed at baseline, 1 month after the second dose, on the day of the booster dose, and 1 month after the booster dose.
RESULTS
Thirty-seven patients were enrolled. At baseline, 15 patients (40.5%) had plaque reduction neutralization titer >10, which is considered protective. Among 22 seronegative patients, 15 (68.2%) and 19 (86.4%) exhibited seroconversion after revaccination and booster dose, respectively. Median JE-specific T lymphocyte counts also increased. Twenty of 111 (18.0%) vaccination doses resulted in self-limiting side effects.
CONCLUSIONS
The inactivated Vero cell culture-derived JE vaccine may be safe and effective for immunization against JE virus in children and young adults who have undergone HSCT.
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